I agree that excluding TFB is a 414(s) safe harbor compensation exclusion. But I don't think that alters the premise that this amendment favors predominantly HCE's, and it seems to me that isn't allowable under 1.401(a)(4)-1(c)(2), or possibly other sections as well - I'd have to look, I dunno offhand.
Excluding elective deferrals is a 414(s) safe harbor as well - suppose all the HCE's defer 18%, and the NHCE's defer 2% on average. Is it ok to allocate the profit sharing contribution on a retroactive correction to include TFB's and elective deferrals, such that the PS allocation now substantially benefits the HCE's far more than without the retroactive amendment?
I'm just saying I wouldn't do this as SCP. Perhaps a VCP would be successful, and then no worries! But everyone else may think I'm nuts, overly cautious, or just plain wrong.
Enjoy the weekend! I expect that what passes for my brain will be going on strike before too much longer...